Little detailed information exists concerning reproduction in most mites and ticks. We propose to investigate various aspects of reproduction in acarines of public health importance. These species represent hard ticks (Ixodidae: Metastriata and Prostriata), soft ticks (Argasidae) and bird mites (Dermanyssidae). Four species will be used to varying degrees depending on the specific experiments. The study will involve (1) histological and histochemical analysis of growth and differentiation of reproductive systems, (2) histological correlation of growth and other responses of non-reproductive organ systems with growth and differentiation of reproductive systems, (3) analysis of the role of nutrition in gametogenesis and development of genital accessory glands, (4) in vivo analysis of endocrine factors on development, (5) in vitro analysis of effects of various compounds on growth and development of male and female genital systems, (6) study of spermatophore production and mating behavior, (7) analysis of effects of mating on oogenesis and oviposition, (8) development of artificial insemination techniques and (9) effects of tretamine on spermatogenesis, genital accessory glands, spermatophore production, mating behavior, sperm relocation in females and fertility.